Half to enoch rutzler



M A H G N N N U 0 Y W 2 Sheets-Sheet 1.

(N0 Mod-e1.)

SAFETY VALVE.

Patented Apr 23, 1889 mine-mm;

UNITED STATES PATENT .OFFICE..

WILLIAM F. CUNNINGHAM, OF BROOKLYN, NEW YORK, ASSIGNOR OF ONE- HALF TOENOOH RUTZLER, OF SAME PLACE.

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 402,070, dated April23, 1889. Application filed January 23, 1889. V Serial No. 297,318. (Nomodel.)

To all whom it may concern:

Be it known that 1, WILLIAM F. CUNNING- HAM, of Brooklyn, in the countyof Kings and State of New York, have invented a certain new and usefulImprovement in Safety-Valves, of which the following is a specification.

My improvement embodies a safety-valve so constructed that it will beoperated both upon the increase of pressure beyond what is required andalso upon the decrease of pressure below normal atmospheric pressure.

I will describe in detail a safety-valve embodying my improvement, andthen point out the novel features in claims.

In the accompanying drawings, Figure 1 illustrates a valve embodying myimprovement, the same being shown in longitudinal section. Fig. 2 is asectional view taken on the line 00 00, Fig. 1.

Similar letters of reference designate corresponding parts in all thefigures.

A is a valve-chamber formed in a shell or case, A. The shell or case isprovided with a port, a, formed in a neck, which is internallyscrew-threaded, to enable it to be attached to a boiler or other sourceof pressure which it is sought to control. The outletport a is normallyopen.

B B designate two valves adapted to sit upon valve-seats 12, formed uponthe interior of the case or shellA. These valves work through suitablebearings, c d, formed as here shown, in cap or plug pieces D D, unitedby a screw-threaded connection with the case or shell A. The bearings cd are formed in spiders E, and the plugs or caps D D are hollow,

so. that when the valves B B are moved from their seats there will be afree communication between the valve-chamber A and the interior of theplugs or caps D D. The plugs or caps D D are provided with apertures e,by which communication is afforded to the external atmosphere.

It will be observed that the valve-seats b b are inward of the spidersE, and that the valves are so arranged that the valve B is within thechamber A, and is adapted to be seated when the pressure coming from theport a, is equal to or greater than normal atmospheric pressure. Thevalve B, on the contrary, is arranged outside the chamber A, and

is adapted to be unseated when the pressure from the port (It increasesbeyond a desired point. I have shown the stem f of the valve B asprovided outside the cap or plug D with a weight, F, which weight servesto hold the valve B to its seat until it shall be moved oif from thesame by an excess of pressure within the chamber A. When the valve B hasbeen moved off from its seat, as shown more clearly in dotted lines,excess of pressure may escape through the openings e in the cap D.

If, now, the pressure from the port ashould fall below normalatmospheric pressure, the pressure exerted by the atmosphere, throughthe openings e in the plug or cap D, will raise the valve B from itsseat and will thus restore the pressure in the system. The valve Breturns to its seat by gravity after the pressure has been restored,said valve being guided in its movements by means of a spindle,

f. The valve B therefore is operated by an excess of pressure, while tievalve B is operated upon the formation of a partial vacuum.

I have shown a plug, G, engaging a neck, g, upon the shell A. Byremoving this plug the valve may be cleaned.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. In a safety-valve, the combination, with a case or shell forming achamber and pro vided witha normally-openoutlet-port, of two separatevalves arranged at different parts of said chamber, one of which isadapted to open into said chamber and the other of which 8 5 opensoutwardly from said chamber, separate communications with the externalatmosphere being established when either of said valves is raised fromits seat, substantially as specified. 9o

2. The combination, with a case or shell, A, having the normally-openoutlet-port a, of the valve B, the weighted valve B, seats for saidvalves within the case or shell, and caps or plugs for the said sh ellaffording 'separate communications with the external atmosphere wheneither of the valves is raised from its seat, substantially asspecified.

WILLIAM F. CUNNINGHAM. Witnesses:

HENRY T. BROWN, FREDK. HAYNES.

